Deep Time, Big History, and Existential Risk

byPaul GilsteronOctober 4, 2013

Nick Nielsen thinks big, as his previous work in these pages and elsewhere has shown. His presentation on “The Large Scale Structure of Spacefaring Civilization” at the 2012 100YSS conference examined humanity’s growth as defined and enabled by the structure of spacetime itself. His continuing work with Heath Rezabek weighs the factors that threaten a technological civilization, while considering what we can do in response. An author and contributing analyst with strategic consulting firm Wikistrat, Nielsen here looks at our concepts of time and the emergence of ‘Big History,’ which might be called ‘history in a cosmic context.’ We are now developing the tools that, used properly, can address and resolve issues of existential risk.

by J. N. Nielsen

James Hutton is often credited with the origins of the modern conception of geological time, which is sometimes called “deep time.” Looking upon the Bass Rock in the outer part of the Firth of Forth James Hutton is said to have remarked, “…the mind seemed to grow giddy by looking so far into the abyss of time.” (The Bass Rock: Its Civil and Ecclesiastic History, “Geology of the Bass,” p. 82) Hutton also became famous for saying of the deep time of geology, “we find no vestige of a beginning, no prospect of an end.”

Deep time is also called geological time, because the order of change in geology, essentially invisible in terms of human time, is revealed in deep time. The deep time of the geological record is time enough for continents to move and reshape themselves, for mountain ranges to rise and fall, and for the planet entire to pass through a range of climates from a glaciated snowball earth to a steaming global swamp.

Image: Geologist, physician and naturalist James Hutton (1726-1797). This is Hutton’s portrait as painted by Sir Henry Raeburn in 1776.

For all this diversity, science has given the peculiar name of uniformitarianism, since although conditions and structures of the Earth change continually, the forces acting on the Earth are uniform over time. Charles Lyell especially developed geology along the lines of uniformitarianism, and this had a great influence on Darwin, who carried Lyell’s Principles of Geology along with him during his journey on the Beagle.

By the late twentieth century, however, Stephen J. Gould was able to argue in his paper “Is Uniformitarianism Necessary?” that to say that geology embodies uniformitarianism is nothing more than to say that geology is a science, and this is not controversial, so that it becomes unnecessary to explicitly formulate uniformitarianism as a scientific hypothesis, which freed up Gould and others studying deep time to consider other models of the past that are slightly less uniform but no less “deep” in the temporal sense (e.g., punctuated equilibrium).

Deep Time in Biology: Astrobiology

It took biologists time to come to a full realization of the antiquity of life on Earth, just as it took geologists time to formulate a time scale adequate to describe the processes of geology. The geologists got there first, but they got there with the help of paleontologists. William Smith, who drew the first modern geological map of England, dated rock strata by the fossils they contained and so established a correlation between geological time and biological time. (This is a story told in the excellent book by Simon Winchester, The Map that Changed the World.)

It is only in our time that we are coming to realize that the geology of the Earth and the life of our planet must be understood in a cosmological context. The formation of the Earth itself was a process that could be characterized as astrophysical before it was geological, and the astrophysics of our solar system continues to this day to shape the surface of our planet.

Life on Earth has shared the fate of the planet that hosts it, and this life has been shaped by cosmological events also. The earth, for example, wobbles in its orbit, and in fact the sun bobs up and down in the plane of the Milky Way as the galaxy spins. The wobbling of the Earth consists of eccentricity, axial tilt, and precession, which together are referred to as Milankovitch cycles, and which significantly affect the insolation of the Earth, i.e., the amount of sunlight reaching the Earth’s surface. This wobbling and bobbing has consequences for life on earth because it changes the climate – sometimes predictably and sometimes unpredictably. But regularity (or, if you prefer, uniformity) is at least partly a function of the length of time we consider.

Astrobiology has come about from the need to see life in its cosmological context, which is as much as to say that astrobiology is the biology of deep time. And we may need time even deeper than that provided by the geology of Earth to explain life. A recent well-publicized study, “Life Before Earth” (see preprint here) by Alexei A. Sharov and Richard Gordon, argued that projecting the complexity of life backward through time implies that life originated approximately 9.7 billion years ago, which is almost twice as old as the earth, which implies in turn that earth was “seeded” with life as soon as it was cool enough to support life (or sufficiently stable to sustain life), rather than independently arising on Earth.

Deep Time for Humanity: Big History

A scientific conception of deep time in geology and biology was the necessary prerequisite to the introduction of deep time into history, which latter was, from its ancient Greek inception up through the twentieth century, a humanistic rather than a scientific discipline. “History” was synonymous with written language, and the “historical period” was the period of human existence coincident with the use of written language.

The relatively recent emergence of what is now often called “Big History” is a result of many factors, not the least of which were the technologically facilitated dating methods that began to emerge in the middle of the twentieth century – most famously, carbon-14 dating. With the ability to date artifacts scientifically, a new and precise chronology emerged in parallel with written chronology, but this new chronology could be pushed far deeper in the past, and thus provide human beings with our own “deep time.”

The best known names in the field of Big History today – David Christian, Cynthia Stokes-Brown, and Fred Spier – have drawn heavily on the many special sciences to assemble an overall “big picture” view that places human history in the context of scientific historiography, wrapping up the whole in a chronology that extends from the Big Bang to the present day.

This Big History picture of human beings and the world in which they live has made us aware of the fact that our planet, our bodies, and our lives have been shaped by forces much larger than our planet, and even larger than our solar system. Ancient gamma ray bursts coming from deep within the galaxy may have affected the path of evolution of life on earth; closer to home, the Earth’s insolation has driven climate, and climate is a primary driver of evolution. So it seems that we are not only “star stuff” as Carl Sagan said, but our star stuff continues its relation to the stars even after it has become Earth-bound.

Ignorance is Bliss

In the early history of our species, ignorance of existential risk was bliss. Human beings, their hominid predecessors, and the species that preceded them in turn, were fortunate merely to survive, i.e., to overcome the immediate existential risks posed by the local climate and conditions and to go on living from day to day. And when the small initial population of homo sapiens was geographically restricted to a small area of Africa, these local risks were profound and potentially existential.

It is widely postulated that human beings passed through an existential bottleneck about 70 thousand years ago (cf. population bottleneck), when there may have been only a few thousand representative individuals of our species alive. This existential bottleneck in human history was once theorized to be the result of the Mount Toba explosion, though recent research has suggested that this is not the case. There is an ongoing debate as to whether this existential bottleneck was a short, sharp event brought about through sudden climatic change (of the sort that might be triggered by a geophysical event) or a “long bottleneck” lasting up to 100,000 years. Whatever the cause, we got through by the skin of our teeth – though we did not know at the time how lucky we were.

Human beings were once an endangered species on the Earth. No longer. No we have made our way into every habitat on the planet (with the exception of Antarctica, unless one counts the scientific bases there) and have ambitions of controlling the climate of the entire planet. The trouble we have gotten ourselves into by the unrestricted burning of fossil fuels could yet be mitigated by geoengineering through the relatively simple and straight-forward means of placing a slight shade between ourselves and the sun (a “Dyson dot” in the terminology of Robert G. Kennedy, cf. Dyson Dots), but this is only one of many dangers that face us that must be understood on cosmological scales of time and space.

Why Existential Risk Now?

Why should existential risk be a concern for us now, when we have gotten along just fine for several hundred thousand years (and Earth before us for billions of years) without any awareness of existential risk? Are we not sounding a bit like Chicken Little proclaiming that the sky is falling? Do we not risk becoming just another doomsday prophet holding up a sign that says that the end of the world is coming?

Existential risk is a concern for us now because we are capable of understanding existential risk in a way that we would not have been able to understand existential risk in the past. The slow and incremental accumulation of scientific knowledge has made it possible for human beings to formulate the idea of deep time and to apply it in turn to geology, biology, cosmology, and even to human history. Just as a conception of deep time was a requisite for the modern scientific study of geology and biology, scientific historiography and big history was a requisite for the formulation of the idea of existential risk.

We have, essentially by dumb luck, made it thus far. This “dumb luck” may be the Great Filter of SETI and Fermi paradox debates, i.e., whatever it was the prevented a slew of other technological civilizations from emerging and crowding our little corner of the Milky Way, which now seems to us (now, that is to say, that we know how to listen) eerily silent. Some may credit it to divine providence rather than dumb luck.

However it happened that we survived, we have survived so far, but we have no guarantee of continued survival. We do, however, have knowledge on our side. Our scientific progress steadily adds to our knowledge of the world, and that makes us ever more clearly aware of our relationship to the wider world, which in this context means cosmology.

How consciousness of existential risk differs from Chicken Little and doomsday prophets is not only in its rational and scientific character, but, just as importantly, in the rational and scientific character of the response to existential risk. Scientific study of the universe can reveal to us the dangers that we face in great detail, and even the likelihood of our having to face them (a sterilizing gamma ray burst is not very likely, but a massive solar flare could very well burn out electrical power grids around the world). Moreover, the same science implies rational, scientific means of existential risk mitigation.

We are not limited to waving our arms and shouting that the sky is falling, or calling for our fellow man to repent because the end is nigh; we can formulate and execute specific existential risk mitigation strategies and measure their efficacy with the same sober scientific precision. And this is exactly what we need, because we can no longer count on being lucky. If the Great Filter still lies in the future, it will not be luck that gets us beyond it, but our own grit and determination.

Comments on this entry are closed.

David CummingsOctober 4, 2013, 14:45

I saw a photo once in one of Gould’s books, a geologist standing next to a huge rock formation. The rock formation was three separate chunks of earth lying atop each other. Each one was a sedimentary formation, with the sedimentary layers clearly recognizable. The bottom piece of the formation was vertical, meaning the sedimentary layers (having clearly formed in the horizontal) were rotated 90 degrees out of their original orientation. Atop of that sat the second piece of the formation, a horizontal striping of more sedimentary rock. Above that, another 90-degree-rotated vertical piece. To truly comprehend what you are looking at in that photo requires you to engage in contemplation of deep time.

As a child I read a book called “A Child’s History Of the World” that opens with a little parable about a bird and a rock. There is an island, a solid rock, far out at sea, one mile cube of rock sticking up above the waves. Once every thousand years a tiny bird flies to the island and sharpens its beak against the rock cliff. When that cubic mile of rock is finally worn away by successive visits of tiny birds, then a single day in eternity has passed. (Not very scientific, but it stuck with me all these years. That story takes me back to the deep time in my own life.)

Thanks for your comment. The story you relate about a bird sharpening its beak on a rock until it is worn away is new to me, but it is very similar to a Buddhist parable of a statue that is worn away by someone rubbing it with a silken cloth once every hundred years. Illustrations like this are valuable for giving a visceral sense of the depths of deep time.

In the context of existential risk mitigation, an awareness of deep time is a necessary condition of understanding exactly what risks we face and what we might be able to do about them, so it is worthwhile to think about these stories and to try to come up with stories of our own that have an immediate intuitive appeal in pointing us beyond the limitations of ordinary human intuitions.

Perhaps, the first order of business for decreasing our existential risk is doing everything we can to support Elon Musk’s plan to colonize Mars. A two planet economy would greatly develop our space capabilities in perhaps a more productive way than a military sponsored (DARPA) 100 year starship plan. Traveling and living in space will be where the rubber meets the road; it will develop a pragmatic toughness that will be needed in challenging the stars. It’s exactly those people who haven’t been born yet, who will making the trip.

The cosmologists, I think, have a lock on deep time. They contemplate a time in the future, for example, when all is red dwarfs, and then black holes, and then–nothing. How far? perhaps 10^130 years, assuming that nucleation doesn’t occur.

Yes, think of these killing machines in the hands of our dysfunctional politicians. Could this be the Great Filter that snuffs out technological civilizations before they can spread into space? In addition to a Doomsday Clock, we need to create a real time Existential Risk Meter that gives us a clear visual picture of our evolving precarious situation. Even a comedic ERM would be nice. Anyone interested in participating?

Note how on The Human Bottleneck graph that while the Black Death caused a notable dip in the human population, by the time of the two World Wars of the Twentieth Century, even the many millions of dead from those conflicts does not even slow down our growing population, now at over seven billion humans.

Cosmologists have the most comprehensive conception of deep time of all the sciences, but cosmological deep time is relatively recent in historical times. Up until Hubble’s work we really had no idea how large the universe is, and it is the spatial scope of cosmology that gives it such a profound conception of deep time. The only point I wished to make in relation to geology was the deep time emerged first in this context. Subsequent science has taken the concept of deep time much further than geology, and I suspect as we come to grips with dark energy and dark matter in the coming century we will need to evoke even more comprehensive conceptions of deep time (as well as more comprehensive conceptions of existential risk).

Your idea for an existential risk meter (ERM) is really a wonderful suggestion, it would be great to see a website (or an app, for that matter) that embodies this idea. The original “doomsday clock” from the Bulletin of Atomic Scientists has become a kind of de facto ERM, as those who adjust the hands on the clock now take account of more factors than only the threat of nuclear weapons and nuclear war.

As for prioritizing any one plan for existential risk mitigation, I myself would like to see a diversity of approaches that embody a degree of autonomy among existential risk mitigation efforts. Just as I would like to see us move our civilization away from exclusive dependence upon the surface of the Earth, I would not want all our eggs to be in one basket for such an effort. Any one effort might fail, with disastrous PR consequences, and it may turn out in the long run that many parallel efforts create both a social and technological milieu that makes such efforts possible.

I have also considered the possibility that the technology required to create a spacefaring civilization may yet prove to be the Great Filter. If antimatter technology is developed, weapons based on this technology will make nuclear weapons look like firecrackers. We have reason to be concerned, and I think that the most profitable way to express this concern is through the study of existential risk and its mitigation. International efforts to slow or stop certain technological developments, while well intended, are likely to become a form of self-sabotage that contributes to stagnation.

You make a good point. Nick Bostrom, who originated the idea of existential risk, uses a graph to demonstrate how human population has continued to grow despite catastrophic wars. In other contexts, I have pointed out that during the ten years of the Vietnam war, human population grew by a billion, and again during the ten years plus of the Afghanistan war, human population again grew by about a billion. But this exponential growth of the human population does not render us “extinction-proof” as some have claimed. Catastrophic ecological collapse has provided us with sobering lessons like that of the Passenger Pigeon, which once flew in flocks of millions and then within a few decades was extinct.

The next bottleneck to be got through will be getting of this rock to provide some redundancy . But when I speak to people they think that’s going to mean THEM being able to holiday on the Moon, Mars etc – millions of earth people taking a space elevator to a space Hilton or something.
What if getting through the bottleneck isn’t like that? I don’t think space travel will ever be something as flippantly used as air travel. What if it means just a few thousand or tens of thousands of people getting out there and starting ‘Homo 2.0’. Sounds like Toba all over again…

Ah the dangers are numerous ! Just as adults can recognize all the deady dangers around their children while children are carefree. Now we children have grown up and we are astonished that we survived. The next stage of life is to reproduce before we get old and give up on youthful pursuits . I believe civilizations age too, and have only a limited prime adulthood to do what needs doing. Start a family on Mars.

I found this to be very interesting, but I can’t help but wonder if we are not at a critical bottleneck right now. Though mankind’s knowledge and recognition of deep time has advanced tremendously, with that growth there is also a chorus of contrarian views and movements – political, cultural and religious – that threaten convergence to an enlightened path to the future and the addressing of deep time opportunities and issues. I wonder if other ETI have passed through similar bottlenecks. And I wonder if this bottleneck will not sufficiently resolve itself in time – ultimately either being the catalyst to planetary exodus or our extinction.

Some care has to be taken when interpreting genetic data on population bottlenecks. A genetic bottleneck does not imply a population reduction. To the contrary, it usually indicates rapid expansion. The prime example is the bottleneck observed in European populations, which stems from the relatively small founding population which came out of Africa. No catastrophe befell the population of Africa, rather a small part of it emigrated and underwent rapid expansion, leading to the apparent “bottleneck”. The rest of the population may still be there (as now in Africa), or have declined and died out for completely unrelated reasons a long time later.

I am not sure if this is the same bottleneck as that from the Mount Toba speculations you cite, but in any case the pitfall is there.

The other myth that I would rather not seen propagated is the “Life Before Earth” unpublished “preprint” by Alexei A. Sharov and Richard Gordon. It is so bad that it hurts, physically, if you have any knowledge of biology at all.

What is missing in these discussions is the existential risk impact of trying to mitigate existential risk. For example, to mitigate against an interstellar sterilizing event that requires building huge, shielded, space arks, might in turn induce other risks as possible futures may be closed off.

P
Your point re: a possible future in which space travel is not something that billions of our fellow humans will ever experience directly. Such a future scenario could well result in humanity expanding so far in space and time throughout the Milky Way Galaxy that Earth may only be a legend for our space-faring descendants – especially if FTL, warp drive systems, and traversable wormholes turn out to either not feasible or non-existent (STL rather than FTL).

One or another of those risks will, this millenium, kill us or knock us far down. Best to insure ourselves by creating a secondary foundation on Mars. Fully realizing that insurence is expensive, but necessary. Mother Earth would miss us if we die in the cradle.

As long as we are on the subject of Deep Time, I would like to point out that the now-obsolete Steady State theory of the universe (Fred Hoyle) — in which new matter is continuously created as the universe expands and there is no beginning and no end — is now somewhat revived.

It’s not called Steady State anymore and it doesn’t apply to our observable universe anymore but is lives on nevertheless in connection with the Multiverse and takes several interesting forms, one of which being Eternal Inflation (see the Chaotic Inflation of Andrei Linde), in which the universe expands the way dough rises and Big Bangs appear the way bubbles appear in rising dough. These pocket universes are infinite in number and the entire process continues without beginning or end.

I know that what I am talking about has many critics, but it does also have many serious supporters and if there is anything to it then the idea of Deep Time is a matter Deep indeed.

Don’t get me wrong, I think the ideal human destiny is interstellar. But the comments on this article, remind me that many people want to sell space colonization as risk mitigation. I just think that it’s a bad value proposition. We could get some risk mitigation as a benefit, but if we actually focus on risk mitigation, we’re going to push space colonization out even farther into the future.

Since the planet that we evolved on is likely to be the most suitable environment we could find, any challenges we face on Earth (resource management, environmental collapse, conflict, and over-population) are likely to be significantly more challenging on an alien planet.

As far as risk mitigating strategies goes, I think space settlement is pretty far down the list in terms of bang for the buck. Generally speaking, when you think of a specific challenge we might face, colonization does not directly address it.

Craig, since there are no stars within 100 light years that could go supernova, that removes the possibility of a gamma ray burst and the immediate need to have a human colony a significant number of light years from earth.

The other frequently cited event that could require us to be off-earth to survive is a major collision of some kind. It’s possible that a super-collision is in our future with the offending body as yet undetected. Possible but unlikely. To mitigate that risk we don’t have to go to another star, just to Mars, or some other location in the solar system.

So I agree with you, risk mitigation should not be the number one consideration in space colony planning. Such a shaky proposition will probably only provoke skepticism.

And as you say, all the other risks on earth (global warming, etc) are in a category that will be present to an even higher degree on other planets. Geo-engineering our own environment to mitigate global warming, for example, is a lot easier than terraforming Mars. Many of orders of magnitude easier.

And as you say, all the other risks on earth (global warming, etc) are in a category that will be present to an even higher degree on other planets.

This may be true, but I think you are missing an important aspect here: The all-eggs-in-one-basket aspect. Say a civilization-destroying catastrophy comes along every 100,000 years. Here, as well as on Alpha Centauri, but at different times. If we are only here, we are gone. If we are both here and there, we can be back here in a couple of centuries. This is a BIG difference.

Not only that, David, but solar engineering also. Wouldn’t it be great if we figured out a way to manipulate, stabilize and form stars to suit our needs? We may not ever even need to worry about the end of life on this planet if we figure out how to do that–plus it’s something to be more concerned about in terms of risk factor. We get something wrong, the whole system could turn on us. We get something right, the gift will keep on giving. I mean, we wouldn’t immediately test this technology on our sun directly (that’d be insane), rather send the tools a couple of light years away, or in a dark space of the universe and see if we could virtually build our own system–a designer galaxy if you will.

Not sure what generation any of you are from, but I remember as a child watching a Japanese anime called Dragonball Z, where insterstellar travel is touched on quite a bit. There was a sapient race called Saiyans who would transform into a giant ape form during a full moon. The Saiyans later found out the science behind their transformation and were able to create artificial moons that emitted the same amount of energy (called Blutz Waves) required for the transformation. Just incredible how things start stringing together as you get older and look back at the things that influenced you as a child. Hahahttp://www.youtube.com/watch?v=2KTFEK-gozQ

I find it interesting that people are talking about colonizing Mars or elsewhere as some sort of measure to ‘save’ the human race from total extinction.

I want to go to Mars so much it’s almost painful, but as an exercise in learning… the increase of knowledge. I agree if we are to survive at all, it will probably need to be off planet. I’m concerned that we, (humans as a group of billions), will just screw up elsewhere though, seeing as we can’t control our primitive urges even now, when we know them for what they are.

We are seven billion on a planet that should hold 2 billion max. We know that, however, on the whole, we are too stupid to figure that we should stop breeding like roaches. Are we worth saving?

Viewed as a large group, we have constant knee jerk reactions to emotional and environmental stimuli… we behave like hysterical teenagers. On a cosmic scale we are small and of no significance. Are we significant enough to ourselves to finally grow up? Looking around the world and hearing what’s on in the news today, we are still dangerous juveniles who shouldn’t be on the cosmic ‘street’.

Do we have an evolutionary ‘use by’ date, regardless of environment? I always wondered, as more and more we see modern medical science (which is a great thing), allowing more and more survivals and breeding of weaker genetic strains. I know, because I am one of them. I have a blood disorder. I should have died early on in the piece. I’ve chosen not to breed because I know that any children I have will have a physical disadvantage that would not serve them in a survival situation, nor would it allow them to do many things that they might wish to do, and cramp their mental abilities. Say, go to Mars, for instance. Who knows what the ultimate consequences would be hndreds of generations down the line? I wouldn’t give my own children a life sentence of frustrated desires, leave alone any one else’s.

I have to query this ‘survival at all costs’ attitude. Everyone thinks about their own genetic survival, as we are programmed to do, and are busily examining results, instead of thinking about consequences. I really don’t worry about the human race becoming extinct, I find it doesn’t really upset me all that much. The thought is a great sadness to me, there is pain at the loss, but I feel that it wouldn’t be so terrible to leave that evolutionary niche free for another species to attempt to fill.

The great tragedy is that we will have taken so many other species with us. We are the drunk driver that kills randomly and without reason, out of control. One drunk driver isn’t statistically significant, but seven billion? We cut a large path through a delicate, world.

Philosofy, in my opinion you judge us too harshly. So we kill randomly and without reason. Well, nature kills randomly and without reason. 99% of all species that have ever lived are extinct. You can’t lay most of those extinctions at our doorstep. Most of them are “natural”. Without rhyme. Without reason. What is the “reason” — in a philosophical sense, not in the sense of material cause — of the Permian extinction, or the other mass extinctions on this planet. Random, without reason. All.

And as far as “nature” goes, the way I see it we are part of nature. We are apes who learned to walk upright and pick up and shape stones. And organize group hierarchies. It’s the most natural thing in the world.

Don’t be so hard on your fellow humans. Most of the ones having more than replacement numbers of babies are much, much, much, much poorer than you or I. They don’t have websites. They don’t have centauri dreams. They have lives brutal and short… and their children. They are not acting drunk or stupid, they are just trying to survive.

Want to lower the birthrate on planet earth? Help raise people up out of poverty. The middle class has fewer children.

Philosofy, we are of course part of nature. There were many millenia passed by here without H.Sapiens. And some day our season too will pass. But no species should let go without a fight. For our kind, that means seed colonies at the desert world(s) nearby.

Here is the parable of the rock island but slightly different, this is a “definition of eternity” Here it is in french as I heard it first:”Imagine que la Terre soit faite de plomb et que tous les mille ans une colombe surgie des fins fonds du cosmos vienne effleurer sa surface de son aile. Lorsque la Terre aura été complétement effacée par l’aile de la colombe, alors seulement commencera l’éternité !” Imagine the Earth is made of lead and once in every thousand years a dove coming from the depths of the cosmos gently rubs its surface with its wing. When the Earth has been wiped off by the wing of the dove, only then will eternity begin

An excerpt from the Herzog/Paglen Last Pictures event in New York City.
Launch footage shows a Proton-M rocket with the Last Pictures onboard heading to geostationary orbit from Baikonur, Kazakhstan, November 2012.

The Last Pictures was commissioned by Creative Time and the Herzog/Paglen event was hosted by LIVE at the New York Public Library in Bryant Park.

I’m sure I read the “bird scratching on giant rock” metaphor in a science fiction book once. The context was describing the age of the universe. I think the book was by Brian Aldiss, but I can’t place it. This would have been in the late 60s or early 70s.

In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For the last eleven years, this site has coordinated its efforts with the Tau Zero Foundation, and now serves as the Foundation's news forum. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image: Marco Lorenzi).

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